Dr. Rayala on incorporating nitrous oxide for transrectal prostate biopsy

In this video, Heidi J. Rayala, MD, PhD, describes the background behind the recent Journal of Urology study “Practical Use of Self-Adjusted Nitrous Oxide (SANO) During Transrectal Prostate Biopsy: A Double-Blind Randomized-Control Trial.” Rayala is an assistant professor of surgery at Harvard Medical School in Boston, Massachusetts.

Transcription:

Please describe the background for this study.

I think part of this just comes from thinking back on 20 years of training and experience. When I started out in my training, I never really thought we'd still be doing prostate biopsies 20 years later. As a physician, I sometimes feel almost apologetic when I have to describe this procedure to patients, to explain that they're going to be awake, and that we're going to be putting a probe in the rectum and moving that probe around, and then taking anywhere from 12, to sometimes up to 20 biopsies. And I think we all know that most patients tolerate it well. But there are some patients [for whom] it's a very traumatic experience, and sometimes it can be hard to predict who those patients will be. We're entering an era of more trauma-informed care, and trying to be sensitive to the fact that some of these invasive procedures can be a trigger for people because they're in that moment of feeling helpless and they don't have really a lot of control over the situation. And so just to be thoughtful of that, I always try to reassure my patients, and I try to be present for them when we're there. However, when I learned about this option of nitrous oxide, I was very curious. I originally assumed there was no way I'd be able to do it, because in my mind, I was thinking, "Okay, this is going to need an anesthesiologist; this is going to need money." But I at least looked into it and was really surprised to find out some of the details. These machines that we're using in the United States use nitrous oxide at what the American Society of Anesthesiologists refer to as minimal sedation. It's inhaled oxygen; it's less than 50%. We call it self administered, because the patient's actually holding the mask to their face. So they're awake and alert and able to hold the mask to their face. But there are a lot of benefits to it. For example, you don't need to have an anesthesiologist present; this isn't moderate sedation, and the patients don't need to be NPO. So even though nitrous oxide relaxes the patient, they still have maintenance of their airway reflexes, so there's not a risk of respiratory depression or aspiration. One of the advantages of nitrous is it's very fast onset and offset. It starts working within about 2 minutes, and after the procedure, it's actually out of the system within 3 to 5 minutes, so the patient can actually drive home. That's actually a benefit over, for example, benzodiazepines that we often currently provide for our ambulatory procedures, because that's a medicine that has a longer onset, and so the patients do require a ride home. This maintains that independence of a patient being able to come in and drive themselves home. It really doesn't add much time to the actual procedure, and there's no recovery period. I think there are a lot of benefits to nitrous oxide, which is what made us reach out to see whether we can start some studies at our institution at Beth Israel Deaconess Medical Center.

This transcription was edited for clarity.